RatedR_RX-8

First off, does anyone know the weight of the factory flywheel? Next on pettit racing's web site they have both steel and aluminum flywheels that are 9 and 8.something lbs. One of my buddies said that if you get a flywheel lighter then 13lbs then your gonna run into trouble but then again this is the same guy who is trying to get me to go to the dark side and trade in my 8 for a WRX. Is there truth to what he says though or is it just him trying to compare whats good for his WRX to my 8?

mikefrombarrie

The stock flywheel with bolts and everything is 21.5lbs

ACTman

Not true. On the WRX the CEL (check engine light) goes off if the flywheel is too light because it is sensing a false knock (assumed from the torsional vibrations). I think this is unique to the WRX. I haven't heard of this on any other applications yet.

Fanman

Most flywheels alone are 9 lbs. & up. If you get an 8 lb. flywheel you may run into trouble. Over on the SR Motorsports they make a comment on how 8 lb race flywheels will give you really bad street driving characteristics.

www.srmotorsports.com

RatedR_RX-8

For everyday driving would you want to get a flywheel that weighs no less then 9 lbs. or just stick with stock?

ddub

I run a 9lb. flywheel on my 2nd gen RX7 and daily drive it. I plan to get the lightest flywheel I can for the RX8.

At first it's a pain, but after about 1 or 2 days you get used to it and it's awesome.

RatedR_RX-8

how is it a pain at first? are you talking about when going up hills? Also when you get a lighter flywheel for you 8 let me know how it does.

ddub

Mainly starting from ANY stop was just a pain at first. I almost killed the car constantly, it was basically like learning how to drive a manual all over again. You have to rev the car a tad higher when starting from a stop with that light of a flywheel (9 lb) so it's just a re-learning process.

MrWigggles

This topic comes around every 3 months.

Do not forget the moment of interia is more important than actual weight. Stated differently, it is where the weight is located on the wheel that makes a difference in performance.

This is why the Mazdaspeed flywheel feels significantly different eventhough it is only about 6 pounds lighter than stock in actual weight.

Many discussions have been done on this. Do a search for "moment" "intertia" "flywheel" for a more info.

-Mr. Wigggles

olddragger

iTrader: (3)

hey,
I installed an act prolite flywheel plus counterweight from auto rx7 and the total weight with all was 13lb 4oz. Great mod. Really changes the car. Absoulutely no driveability issues even with the a/c on.
olddragger

MrWigggles

BTW,

I almost forgot to mention. The driveability with the MS flywheel for me was BETTER than stock.

-Mr. Wigggles